The government should publish a target by 2020 for achieving "net zero" emissions, according to a new report.

The report says that while the UK has maintained a consensus on the need for action on climate change, buy-in across government departments is “too uneven”

The report entitled ’10 Years of the Climate Change Act’, published last week by the Grantham Research Institute at the London School of Economics, says the target to cut emissions by 2050 to 80 per cent of 1990 levels is “technically consistent” with the Paris Agreement.

But to ensure the UK is able to meet the agreement’s objective of keeping temperature rises “well below” 2 degrees C, the report proposes the government should go further and set a supplementary zero emissions target that would also cover the period after 2050 when the act ceases to have force.

The report also recommends that the publication of the government’s carbon reduction plans should be subject to a statutory deadline to avoid delaying the implementation of efforts to tackle climate change.

As an example of the stronger accountability mechanisms it says are required to safeguard the Climate Change Act (CCA), it suggests the act should be amended to create a statutory response time for the government to publish its carbon plans.

The government was widely criticised by environmental groups for taking nearly 18 months to respond last November with the Clean Growth Strategy to the 5th carbon budget, which had been passed in July 2016.

And the report says that while the UK has maintained a consensus on the need for action on climate change, buy-in across government departments is “too uneven”.

“All parts of government must be fully committed to the implementation of the act as the UK moves into a more challenging phase of emissions reductions.”

The report also raises worries that the CCA does not contain sufficiently robust safeguards against “back-sliding” on efforts to tackle climate change.

“There is concern that without enforcement action the gap will continue to widen between the emissions targets set in law and the policies put in place to deliver those targets.”

And it warns that efforts to tackle climate change over the next decade are likely to prove “more difficult” with the UK currently off track to meet its statutory carbon targets for the mid-2020s and early 2030s.

In addition, while the report says the CCA has provided investors with certainty about the trajectory of carbon reduction targets, it has succeeded to a “much lesser extent” vis-à-vis the policies to implement its objectives.

The Grantham Centre report was published in the wake of new government figures showing that carbon dioxide emissions continued to fall in 2017.

The figures show that UK net emissions of carbon dioxide were provisionally estimated to be 366.9 million tonnes (Mt) in 2017, 3.2 per cent lower than the 2016 figure of 378.9 Mt.

It finds that the decrease in emissions of CO2 was mainly caused by an 8.7 MtCO2e fall in emissions from the energy sector, which was in turn driven by the switch from coal electricity generation to gas and renewables.

The fall was also buoyed by a 2.9 MtCO2 fall in household emissions due to a decrease in the use of natural gas for space heating because temperatures were relatively warm during the year.

Transport remained the largest contributor to CO2 emissions in 2017 after outstripping energy supply for the first time last year. The transport and energy sectors accounted for an estimated 34 per cent and 29 per cent respectively of CO2 emissions, which make up 81 per cent of all UK greenhouse gases emitted.